Electric signaling system



A. BROWN ETAL ELECTRIC SIGNALING SYSTEM Dec. 2s, 1.948.

e Shets-Sheet 1 Filed Jan. 12, 1944 L 6 OK INVENTOR. ANDREW BROWN THOMQ? ALFRED MARSHALL A TTOI-PNEY Dec. 28, 1948. A. BROWN ET AL 2,457,121

ELECTRIC SIGNALING SYSTEM Filed Jan. 12, 1944 a Sheets-Sheet 2 FIG. 2A

IN V EN TOR.

ANDREW BROWN THOMAS ALFRED MARSHALL.

A rroR/vey Dec. 28, 1948. A. BROWN ET AL 2,457,121

ELECTRIC SIGNALING SYSTEM Filed Jan. 12, 1944 e Sheets-Sheet 3 FIG. 3A

' INVENTOR. ANDREW BROWN THohg s ALFRED MARSHALL A TTOPA/Elf Dec. 28, 1948.

'A. BROWN ET AL ELECTRIC SIGNALING SYSTEM 6 sheets-sheet 4 Filed Jan. 12, 1944 INVENTOR.

BY ARSHALli ANDREW BROWN THOMAS ALFRED M A TTORNEV Dec. 28, 1948. I A. BROWN E ELECTRIC SIGNALING SYSTEM 6 Sheets-Sheet 5 Filed Jan. 12, 1944 mm 0E INVENTOR.

THOMAS ALFRED MARSHALL AN DR'EW BROWN A TTORNEV Dec. 28, 1948. A. BROWN ET AL 2,457,121

' 'ELECTRIC SIGNALING SYSTEM Filed Jan. 12, 1944 a Sheets-Sheet '6 INVENTORL ANDREW BROWN THQg/IAS ALFRED MARSHALL A TTORNEV Patented Dec. 28, 1948 2,457,121 ELECTRIC SIGNALING SYSTEM Andrew Brown and Thomas Alfred Marshall, London, En a assignors, by

mesne assignments,

to International Standard Electric Corporation,

New York, N.

Y., a corporation of Delaware Application January 12, 1944, Serial No. 517,970 In Great Britain February :9, 1943 This invention relates to train-describers for supplying information to railway signal cabins and like locations.

One of the objects of the invention is to provide a simple traindescriber suitable for use where the number of train descriptions to be stored at any one time and/or the variety of such descriptions are small. Another object is to provide a train describer which utilises almost nothing but relays for its functioning.

An embodiment of the invention will now be described; reference being made for this purpose to the accompanying drawings in which:

Figs. 1A and 1B show the transmitter circuit;

Figs. 2A and 2B show the reception and prestorage elements of the receiver circuit;

Figs. 3A and 3B show the storage elements and the display elements of the receiver circuit; and

Fig. 4 is a block diagram showing the arrangement of the circuits of Figs. 2A, 2B, 3A and '33 with respect to each other.

This has the added advantage that in most areas the trains with which a signalman is directly concerned would all have the same initial code digit. Thus a signalman'in sub-area 1 would usually only need to set up special routes for trains having destinations in his sub-area, and therefore would know that all trains indicated as being for sub-areas 2, 3 or '4 would be main-line, through, trains. The Signalman requires to-know the full description of each train passing his {box even though he has no special function to perform in relation thereto.

The destinations for all areas are indicated by the code letters A-'G, but each indicator may also carry indications of the particular destinations of the sub-area in which the box "is situated in order to facilitate 'handiing'local trail-"1c.

The actual destinations indicated on the panels will, if given, vary from sub-area to sub-area.

The indicator described therefore comprises only eleven .sections per train to indicate the maximum of twenty-eight different destinations, a possible saving of seventeen sections. .At the same time, the Signalman is given .a simple method of determining whether a train is within his sub-area; if he .is in sub-area l, he .is "only directly concerned with trains "for which the unit 1 is illuminated or otherwise shown.

Generalcir'cuit'ope'ra'tion circuits.

Referring to Figures lA'and ,1B the code record which describes a train is set up on a description set of relays SA, SB, SC, by means of keys SAK, SBK and SCK. These relays lock in series with common relays and start a pulsing relay MTR into operation which continues to pulse without sending anything over the line until the operator depresses the TK ke and immediately releases it. The pulses then operate the impulse counting relays CA to CJ in pairs. As these counting relays progress, plus and minus are sent over lines Li and L2 in the direction corresponding to the records set up on the description set of relays. For example, if relay SA is not operated, the .first pulse will he sent of .a polarity which will not record at the receiving end.

There are also certain checking circuits which check to see if the correct number of pulses have been sent, and, if not, the operator will be apprised. At the receiving end, .in Figs. 2A two relays IR and IP are connected across LI and L2 in parallel, each in series with a rectifier. the rectifiers being oppositely poled, thus making them the equivalent of polarized relays. The-pulses received by the apparatus of Fig. 2A always operate one or the other of these equivalent polarized relays, either of which will operate pairs oicounting relays (Fig. 2B) and one only of which will record on the prestorage relays the record corresponding to that set-up on the description set of relays at the sending end.

After the record has been completed on the prestorage relays (Fig. 2B.) this record is transferred to the regular storage group selection relays (Figs. 3A and 3B). These storage group selection relays, SCA, SCB, SCC, and SCD, are always operated in sequence :in the order named, being normally connected so that at the proper time the record from the prestorage relays is transferred to the first group of storage relays. This-makes the-secondgroup of relayseiiective for receiving the next-recordand the prestorage relays and allrelays in Figures 1A, 113, 2A and 2B are released after a check :has been made. The record :set up on the prestorage relays is then transferred to .a second :group in the regular storage group "relays.

Setting :up

of .relay'SB may betraced from negative battery 3 through the winding of MSR, contact SK3, contact SC3, key SBK, winding of SB, contact SAZ, contact RF! to plus battery. The relay SB locks in series with the relay SPR and reset key RK. The locking circuit for relay SB may be traced from negative battery, right hand winding relay SB, contact SBl, winding relay SPR, contact MSR2, key RK to plus battery. The operation of the relay MSR selects this holding circuit so that should the signalman set up a description in error he can reset the describer'to normal' from vibrating under self-interruption and compels it to energise and de-energise uniformly producing a steady impulsing. (The relay MTR and associated parts could be replaced by a pendulum relay.)

This impulsing is applied to the set-up lamp SBL via contacts MTRB and SEE indicating to the signalman which description has been set up.

The coding system used on this describer consists of a train of impulses the total number of impulses in each code being equal to the number of set-up relays (4 in this case). The normal polarity of these is negative applied to line I, and so that the receiver can distinguish which code has been transmitted, the impulse allocated to the particular description set up is given a l reverse polarity by the operation of the set-up relay. In the case of the description allocated to relay SB, its contacts SE4, 5, in the line circuit reverse the polarity of the impulse.

' Transmission When the signalman has checked that the description set up is correct he can transmit it by operating and releasing the transmit key TX, to operate relay 'I'RG and then relay TPR While relay TRG is releasing. The circuit for the operation of relay TRG may be traced from negative battery through the winding of relay TRG, contact TK front, contact MSRI to plus battery. Relay TRG is slow releasing, so that while it is releasing relay TPR operates over the following circuit: negative battery, relay TPR, contact TRGZ, contact TK back, contact MSRI to plus battery.

The relay TPR holds over its oWn contact TPRG, and contact CJ I and contact MSRI front to positive battery.

The operating of relay MSR has completed the line circuit over contacts MSR3 and MSRQ.

The impulsing of relay MTR is started with the operation of relay MSR andoperates the counting relay over contact MTRZ. When contact MTR2 makes, relay CA operates. The circuit for CA may be traced from negative battery,

winding of CA, back contact CBI, contact MTRZ,

contact TPRZ to plus battery. When contact MTRZ breaks, relay CB operates in series with CA over contact CAI. The operation of relay CB routes the next pulse to relay CC over contact CBI. This cycle of events continues until relay CJ operates and releases relay TPR over contact CJI.

Consider now the effect the operation of the counting relays has upon the line circuit.

On each operation of relay MTR the next of the odd relays CA, CC, CE, etc., is operated, which on each release of relay MTR the next of the even relays CB, CD, CF is operated in series with the companion odd relay. Thus at each release of relay M'I'R the signal-source is connected towards the line over contacts of the successive set-up relays SA, SB, etc. The first pulse over the line may be traced from negative battery at the upper left corner of Fig. 1A through a resistance, contacts SA3 back, CB2, CD2 back,

'CFZ back, CH2 back, MTR4, MSR3 front, FPR2 back, to line. I. The return may be traced from plus battery through contacts SA4 back, CB3

front, CD3 back, CF3 back, CH3 back, MTR5, MSRA front, FPR3 back to line 2. The circuit through the SB contacts is reversed and may be traced as follows: Negative battery upper left corner of Fig. 1A, resistance, contacts SE5 front, CD3 front, CF3 back, CH3 back, MTR5, MSR4 front, FPR3 back, to line 2. The plus battery may be traced through contacts SE4 front, CD2 front, CFZ back, CH2 back, MTR S, MSR3 front, FPR2 back, to line I, thus sending the battery for this pulse in the reverse direction to operate a relay of the receiving end corresponding to relay SB. The actual signal-sending does not occur however until the next operation of MTR when contacts MTR4 and 5 close.

Thus the sequence may be represented as follows:

Impulse Counting operates for the third time...

released for the third time...

se. relay CE operates... start of second relay CF operates... end of second p .se.

and so on. I

The polarity of the line pulses is determined by the condition of the several set-up relays SA, SB, etc.; so that in the case being described, where relay SB is operated and allthe others not operated, the second line pulse will be plus battery on line I and all the others will be minus battery on line 1.,

The last impulse is transmitted when relay MTB. operates for the fifth time,'relay CI also operating.

When relay MTR releases relay CJ operates, releasing relay TPR over contact CJ l, thus deenergising all the counting relays so that impulses are no longer sent to the receiver by further operations of the relay MTR. When relay MTR releases after the last impulse, relay CJ operates and relay FPR is operated over contacts CJZ and MTR3, holding over contacts FPRI, TRG3, MSRI. The operation of relay FPR connects the relay RC to the line via contacts FPR2, FPRt, and if the code has been received correctl a pulse is sent back ever the line in the proper direction to operate relay RC which holds over its contact RC! and contact MSRI. The operation of relay RC releases the relay MSR over contact RC4, thereby releasing relays FPR. RC and MTR. The release of the relay MTR stops the set up lamp SBL flashing and maintains a steady illumination of that lamp at contact MTR6, giving an indication to the signalman as to which deanimus SPR and SB over a back contact of the set up keys via contact MSR2, so that when he wishes to make another set up, the operation or any set up key releases the relays SPR and SB, thus bringing the chain lockout circuit into operation again cancelling the last sent indication. It will be noted that the contact TPR3 is in parallel with the reset key RK to nullify a y attempt to reset the description during transmission.

Faulty transmission If the code is mutilated during transmission no pulse will be sent back to operate relay RC. A visual indication of this fault being given by the illumination of a fault indication lamp FII through-contacts FPR'! andRC3.

The signalman can retransmit the code as previously described or reset the description by operating the reset key RK.

Cancelling and resetting The operation of key 'RK since .relay MSR is still operated releases the relays SPR and ,SB, relay SPR releasing relay 'MSR. If the signalman should require to cancel the last sent description, he can make a request for cancellation by operating the set up key SKK and transmitting the code as previously described, the set up lamp SKL flashing as for an ordinary description. The cancellation of a vcode is not effective until acknowledged by the signalman at the receiving point, and the acknowledgment is in the form of a pulse of opposite polarity to that used to operate the relay RC. If the code for cancellation is received correctly, the pulse to this effect operates relay RC which releases relay MSR and. gives a steady illumination of the lamp SKL. On the release of relay MSR relay 'FPR will remain operated to receive the acknowledgment pulse, and the back contacts of the set up keys SAK, SBK, and SCK will be short circuited through SKZ front to prevent the set up of another description. When the reversed acknowledgment pulse is received relay AC operates, holding over contact AC1, and releases relays SPR and SK over contact AC2. The release of'relay SK releases relays FPR and AC, and extinguishes the set up lamp SKI. through the opening of contact SK'I. When relay AC operates and releases an audible indication is also given by a buzzer in series with contact AC3.

Receiver full When the total number of descriptions that the receiver is capable of storing has been transmitted, that is to say, when all but one of the storage groups is occupied, then the condition among the storage group selection relays SCA, 803 (Fig. 3A), SOC, SCD (Fig. 3B), and the master storage relays MDA, MDB (Fig. 3A), MDC, MDD (Fig. 3B) is that there are operative both a certain relay SC and "the next later relay MD; for example, both relays SCA and MDB, or both SCC and MDD. With "this condition,

the receiver full relay RFR operates (Fig. 2A)

and at RFRI disconnects the receiving system IR, IP from the line and instead applies to the line a steady current to operate relay RF in the transmitter, relay RF being normally across the line. The operation of relay RF illuminates the Receiver Full lamp RFL over contact RF2 and removes positive from the operating circuits of the "set up relays over contact RF! (extreme upper left of Fig. 1B) so that no further set up or transmission can take place.

releases the relay CAR which in Relay 1B or IP Relays 0, 0A, E figg 1st operation.

1st release O operates on operates. 2nd operation.-. CA operates with O 2nd release E operates, 0A and 0 release... CB operates. 3rd operation. E releases It will be seen therefore that at the end of the first impulse relay 0- operates and at the end of the second impulse relay E operates, this cycle continuing throughout the impulsing. At the same time the successive counting relays operate at the end of each impulse; which among the pre-storage relays AA, AB, AC and AD, only those are operated which correspond to impulses of reversed polarity, i. e. relay AB in the present case.

During impulsing relay RG remains operated due to the slugging effect produced by the condenser QA. But when the impulsing is completed relay RG releases completing a circuit for the relay OK from positive, relay contacts RGAI, 1192 back, 1R2 back, RG3 back, CD3, CE2. The operation of the relay OK sends a negative pulse back to the transmitter over contacts 0K2 front, RFRI back, KAN3 back, to LI and positive over 0K3 front, RFR2 back, and KAN2 back to L2, thus acknowledging the receipt of a code as previ-, ously described. If a code is received containing less than the total number of impulses the relay CD will not operate, and if more than the total number are received the relay CE will operate. Therefore, if relay CD does not operate or relay CE operates the circuit for the relay OK will be incomplete and the pulse will not be sent. The release of relay RG releases relay RGA thereby removing positive from the counting and storage relays and resetting the receiver to normal.

If the code received is a request for cancellation the fourth pulse will be reversed thereby operating the relays IP and AD. When the relay RG releases, relay CAR will operate in parallel with relay OK through contact AD2, the relay OK holding over contacts CARZ and OKI, and the relay CAR also holding over contacts CARI and KANI. The operation of the relays OK and CAR prepares the circuit for the relay KAG, and until this circuit is prepared any operation of the acknowledgment key KAK is ineffective. With the operation of the key KA-K relay KAG energises through contacts 0K4, CAR4 and KAK to plus battery, and since relay KAG is slow to release when key KAK is released the relay KAN willoperate through contacts KAG2, KAK, CSRI to plus battery. When the relay KAN operates a pulse is sent to the transmitter over contacts KANZ front and KAN3 front putting positive on LI and negative on L2, to reset the transmitter to normal. The operation of relay KAN also turn releases relay OK.

Transfer from pre-storage to storage Consider now the efiect the operation of the pre-storage relays has on the storage relays DAA to DAC, etc., Figs. 3A and 3B. Associated with each storage group is a master. storage relay (MDA, MDB, MDC, MDD) which operates in series with the storage relays and denotes that the storage group is occupied, also a storage group, selection relay (SCA to SCD) which when energised prepares its storage group to receive the'next description.

The group selection relays are energised by the occupation of the storage group in front as denoted by the energising of the master storage relay. For example, relay SCA is energised by the operation of the relay MDD, and relay SCB by relay MDA. When the receiver is empty none of the master storage relays is energised, and relay SCA is energised from negative through SCA, over back contacts of SCDZ, SCBB, SCCii, MDA2, to positive, to direct the first description received into its corresponding storage group.

Assuming that the receiver is empty and that the first code to be received is the one previously described; the relay SCA will already be operated closing its contacts SCAG so that when relay OK in Fig. 2A operates and connects positive to the leads supplying the various relays over contact K5, relayDAB will operate in series with relay MDA via contacts 0K5, ABZ, SCA l, left winding of relay DAB, right winding of relay MDA, to negative battery, the relay AB having been previously operated by the reverse pulse in the code. The relays DAB and MDA hold in series with each other. Relay SCA which releases at contact MDA2 will not release immediately relay MDA operates, as it is held over contact SCAI until positive is removed by the release of relay OK, thus preventing the 0K pulse being passed into the next storage group as the operation of relay MDA operates relay SCB over contact MDA3. It will be seen therefore that as each storage group is occupied the circuit for the next storage group is prepared by the operation of its storage selection relay.

When the storage group DDA to DDC is occupied the relay MDD energises the group selection relay SCA. It will be seen therefore that the first description to enter the receiver will always occupy the storage group DAA to DAC and all subsequent descriptions will occupy the storage groups in cyclic order, i. e. the first description will occupy storage group DAA, second description storage group DBA, third description storage group DCA, fourth description storage group DDA and the fifth description storage group DAA, thus causing the cycle to repeat. Assuming that the second description is behind the first so that when the first description is cleared out the second-description is revealed it may be considered that storage relay DBA is behind relay DAA, relay DCA behind DBA, and relay DDA behind DCA; continuing the cycle relay DAA is considered behind relay DDA.

To locate the storage group holding the first description an extra storage group is added. For example, if the maximum number of descriptions to be stored is three then the receiver would require four storage groups. Considering the effect of this extra storage group, it will be seen that if the storage group DAA holds the first description then storage group DDA cannot be occupied since it is only possible to have three descriptions in the receiver at one time, and:

that storage? group DAA is behind DDA; :jSimilarly' receiver holds 1,2 or 3 descriptions the 1st description will, always be the one immediately behind an empty storage group.

Remooal of stored description by cancellation or clear out In the case of removal by cancellation or by clear out the description to be removed will always be either immediately in front of or immediately behind an empty storage group.

When' clear out or cancellation takes place positive is applied over contacts of therelays CSR, or KAN to each storage group Figs. 3A and In the case of a clear out this positive is applied via back contacts of the preceding master storage relay so that the only storage group to be affected will be the one following an unoccupied storage group, e. g. if the receiver has the storage groups DAA, DBA and DCA occupied, the masterv storage relays will render the clear out circuit for storage groups DBA DCA and DDA ineffective over the contacts MDA4, MDB4 and MDC4 respectively. Since the storage group DDA is urioccupied the relay MDD will be de-energised and when relay CSR in Fig. 2Aoperates, positive will beapplied via contacts CSRZ and MDD4 (Fig. 33 right) to short circuit the particular description relay energised in that group. When this positive is removed the relay MDA will also be de energised.

In the case of cancellation positive is applied via back contacts of the succeeding master storage relay so that the only storage to be affected will be the one preceding an unoccupied storage group. As in the case described for clear out the energising of the master storage relays will render the cancellation circuit for the storage groups DDA, ,DAA and DBA ineffective over the contacts MDA5, MDB5, and MDC5.

Display .;Consider ,now the display of the description on the indication panel, and as it is unnecessary to display all the descriptions stored this circuit is designed to display only the 1st and 2nd. It has already been shown how the first description always follows an emptystorage group. Therefore by including a back contact of the master storage relay of the preceding storage group in series with contact of a particular master storage relay the description held by the associated storage relay will be illuminated in the first display. For example if the description associated with relay DAA had to be displayed as the 1st description, the circuit for the display lamp would be from plus battery via contacts MDA6, MDD? and DAA2 through lamp AXL to negative battery. If this description had to be displayed as the 2nd description, it would mean that relay MDD would lee-energised and the circuit for the display lamp would be via contacts MDA6, front contact MDD'I, back contact MDCB, front contact DAA3, and lamp AYL to negative battery. If this description is held in the 3rd storage awaiting display it will be seen that relay MDC would be energised since MDC marks the storage of the 1st description. Therefore the circuit prepared by front contactiMDl lli and front contact MDD! would be interrupted over contact MDC8. When relay MDC releases after a clear out it will be seen that the circuit for the 1st display would be broken over contact MDC6 and would be replaced by a circuit via contacts MDDB and back contact MDB'I, thereby stepping the 2nd display into the 1st. The release of relay MDC also completes the circuit via contacts MDAB, front contact MDD? and MDCB so that the 3rd description is stepped into the 2nd display.

What is claimed is:

1. A train describer comprising a plurality of groups of relays each group arranged to store a train description according to the selective operation of individual relays within the group, a group of prestorage relays, oppositely polarized receiving relays, means for passing the description immediately from said oppositely polarized receiving relays to said group of prestorage relays and relay means for subsequently transferring the description in said group of prestorage relays to the appropriate group of storage relays and for transferring successive descriptions from said prestorage relays into successive groups of said storage relays in a closed cyclic order.

2. In a train describer as claimed in claim 1,

means for checking the correctness of the train description received directly by said group of prestorage relays, and means to control the means for subsequently transferring the train description by said checking means.

3. A train describer comprising a plurality of groups of relays, each group arranged to store a train description according to the selective operation of individual relays within the group, means to limit the maximum number of stored descriptions to one less than the number of said storage groups, relay means for directing successive descriptions into successive groups in a closed cyclic order and means for interrupting said order, to the extent of substituting a new description in the last relay group.

4. A train-describer according to claim 1, in which means are provided for storing a lesser number of train descriptions than the total number of said relay groups so as to leave certain relay groups in non-stored condition, means for cancelling the last stored description in a relay group to render that group available for a subsequent storing operation, and means for directing the next train description to be stored into said available group instead of directing it into the next succeeding group.

5. A train-describer according to claim 1 in which means are provided for storing a lesser number of train descriptions than the total number of said relay groups so as to leave the remaining groups available for receiving other train descriptions, means for directing successive descriptions into said available groups, means for clearing out existing stored descriptionsfrom said groups, said directing and clearing out means being operated in a predetermined succession, and means controlled by said clearing out means to shift said connections to cause said indicating means to display the train description stored in successive groups of relays in the same predetermined order.

6. A train-describer according to claim 1, in which means are provided for storing a lesser number of train descriptions than the total number of said relay groups so as to leave certain groups available for subsequent storing, relay means for directing a subsequent description to be stored into the next relay group following the group containing the last stored description, means for cancelling the last stored description, and means distinct from said cancelling means for clearing out the first stored description.

7. A train-describer according to claim 1, in which means are provided for storing a lesser number of train descriptions than the total number of said relay groups, means for directing successive descriptions into successive relay groups, and means for cancelling the last stored description in a relay group and for directing the next arriving description into that same relay group.

ANDREW BROWN. THOMAS ALFRED MARSHALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

